This is a resubmission of an Independent Scientist Award (ISA) application. It proposes a research program based on longitudinal, cross-sectional, and cross-sectional/longitudinal studies to help identify factors which underlie the perpetration of violence, with special reference to the interaction between social and biological risk factors. Four main programmatic aims are (1) to map the interface between biological and social risk factors for violence and antisocial behavior (2) to assess the role of brain dysfunction in contributing to violent and antisocial behavior (3) to ascertain whether good biological functioning can protect the individual from later violence (4) to investigate the contribution of alcohol abuse, drug abuse, hyperactivity, and schizotypal personality in mediating brain dysfunction - violence relationships. This program of longitudinal research is based upon three current R01 and R03 grants, one recently completed R01 grant, and one proposed grant application. The first four grants form the basis to the more immediate goals of the research program. The applicant's long-term goal is to establish a research career on the causes of violent and antisocial behavior that focuses on the interface between social and biological risk and protective factors. The rationale for this focus is that it is felt that both social and biological processes will be required of any complete explanation of the development of violence. To achieve this goal, the applicant needs to develop new expertise on (a) psychosocial influences on violence (b) psychopathological influences (c) more traditional criminological theories which can be conceptually integrated with the biosocial perspective, (d) molecular and behavioral genetics (e) neurochemistry, and (f ) brain imaging. These skills will be developed in the context of a 10-component research training plan. Such expertise will help the applicant develop a more broad-based, interdisciplinary perspective on violence which is an integral feature of the biosocial approach. It is thought that the training and research plans provide a unique opportunity to address a crucially important, yet relatively neglected, area of interdisciplinary research and which in turn holds the promise of realizing original and potentially major advances in our understanding of the development of violence.